Faculty of Technology

There have been increasing efforts in recent years to minimize the amount of cement used in concrete. Efforts at partial replacement have been successful and regulations have been promulgated to standardize and use such formulations. Research aimed at complete replacement of cement by activating industrial materials that are rich in silica and alumina with alkaline solutions is still on-going all over the world. The present study was aimed at complete elimination of cement through the development of a geopolymer concrete containing the mixture of fly ash and ground granulated blast furnace slag (GGBS), activated by sodium based alkaline activators. The effect of replacing up to 50% fly ash by GGBS was considered. The strength parameters were studied for a mixture of sodium silicate and sodium hydroxide solution having concentration 12M. The samples were cured under ambient conditions as well as in an oven at 60oC for 24 hours. Compressive and split tensile strengths of the samples were measured on 3rd, 7th, 14th, 28th, 56th and 90th days of casting. The cubes were also tested for durability parameters by ponding in NaCl and H2SO4 solution for 28 and 90 days. It was observed that replacing fly ash with 30% of GGBS gave the best results.

Abstract. Construction of tall chimneys is now the basic requirement and has been possible with the advent of latest building technologies and also with better understanding of loads acting on them to determine its structural behaviour. With the experience gained in the chimney design and construction over the years the present-day challenge is to prevent the deterioration of chimney shell and brick lining and thereby increase the service life of the structure. This deterioration is caused due to penetration of flue gases through cracks in the air space, which causes acid attacks and eventually leading to the mortar and concrete erosion. In recent years, many chimneys have been repaired or designed considering borosilicate glass blocks as lining material in lieu of conventional fire brick linings. This study has been done considering brick lining and borosilicate glass block lining for chimneys with 100m and 200m height with temperatures varying as 100oC, 150oC and 200oC. Total 12 chimneys were designed and comparison is done in terms of the overall cost of the material consumed in these chimneys. It was observed that the chimneys constructed with borosilicate blocks as a lining material were 10-12% cheaper than those constructed with conventional brick as a lining material.

Construction of tall chimneys has been possible with the advent of latest building technologies and also with better understanding of loads acting on them to determine its structural behaviour. With the experience gained in the chimney design and construction over the years the present-day challenge is to prevent the deterioration of chimney shell and lining due to penetration of flue gases through cracks in the air space. Recently many chimneys have been designed considering borosilicate blocks as a lining material. It has also been reported about repairing the deteriorated chimney by removing the conventional fire bricks and applying borosilicate block on the chimney shell. In this paper, the engineering properties of both the lining materials are compared. Also, the analytical study has been done on 12 hypothetical chimneys with 100m, 150m and 200m height and the temperature varying at 150oC and 200oC to gauge the effectiveness borosilicate glass blocks in terms of temperature gradient, forces induced and material cost. The study shows that borosilicate block can be a suitable replacement of conventional fire bricks, used as lining for reinforced concrete chimneys, in terms of its application and its engineering properties that govern structural parameters.

Abstract— There have been increasing efforts in recent years to minimize the amount of cement used in concrete. Efforts at partial replacement have been successful and regulations have been promulgated to standardize and use such successful formulations. There is now worldwide research aimed at complete replacement of cement by activating industrial materials that are rich in silica and alumina with alkaline solution. The present study was aimed at complete elimination of cement through the development of a geopolymer concrete containing fly ash and ground granulated blast furnace slag (GGBS), activated by sodium hydroxide based alkaline activators. The effect of replacing up to 50% fly ash by GGBS was also studied. The strength parameters were studied for a mixture of sodium silicate and sodium hydroxide solution having concentrations from 2M to 12M. The samples were cured under ambient conditions. Compressive and split tensile strengths of cubes and cylinders for all mixtures were measured on the 28th day of casting. Good compressive strength was attained with most of the mixtures. The overall data pertaining to compressive strength and chemical components along with curing temperature were collected and compiled to achieve generalized predictable results. Comparative charts were developed in terms of temperature, % of NaOH and SiO2/CaO for compressive strength.

Abstract. Flat slabs structures are the structures with the slabs directly resting on the columns. Due to the absence of the beams the stiffness of the frames reduces resulting in poor performance under the action of lateral loads. The main concern in the flat slabs structures is punching shear that can lead to progressive collapse of the structure. These shear stresses are enhanced due to lateral loads or bi-axial moments which are transferred from slab column connection. This study focusses on effect of the shape of the columns Circular, L, T and Cross on punching shear stress with respect to Indian, American, European and British codes. Total 12 models of a 10 storey building were considered keeping the floor plan area (25m2) constant and varying the panel sizes (5m x 5m, 8.33m x 8.33m, 5m x 8.33m) as well as the shapes of the columns. The structures were analyzed and it was observed that while Eurocode 2 code was more on the conservative side, L and T shaped columns were more suitable in resisting punching shear stress.

Since last few years Concrete Technologists are putting in continuous efforts to minimize the consumption of cement in concrete. Cement offering architectural freedom and being second highest consumed material on earth is also the major cause for CO2 emission in atmosphere. With limited natural resources, durability issues and higher embodied energy, a need is felt to lessen or curtail the use of cement in concrete and replace the same with immensely available industrial by-products such as fly ash and GGBS. These materials, when activated by an alkaline solution exhibit similar strength and durability properties of that of conventional cement concrete. To understand the structural behaviour and crack development pattern, reinforced beams from Geopolymer concrete with fly ash and GGBS as source materials and that with OPC were cast and tested in laboratory. Two points loading was applied and observations were made till ultimate failure load. Also crack development patterns were studied. Similar tests were also done on the beams without reinforcement. From this study similarity in structural behaviour of beams with OPC and that of Geopolymer concrete from fly ash and GGBS can be revealed and hence it can be a potential material for construction industry in future.

There have been increasing efforts in recent years to minimize the amount of cement used in concrete. Efforts at partial replacement have been successful and regulations have been promulgated to standardize and use such formulations. Research aimed at complete replacement of cement by activating industrial materials that are rich in silica and alumina with alkaline solutions is still on-going all over the world. The present study was aimed at complete elimination of cement through the development of a geopolymer concrete containing the mixture of fly ash and ground granulated blast furnace slag (GGBS), activated by sodium based alkaline activators. The effect of replacing up to 50% fly ash by GGBS was considered. The strength parameters were studied for a mixture of sodium silicate and sodium hydroxide solution having concentration 12M. The samples were cured under ambient conditions as well as in an oven at 60oC for 24 hours. Compressive and split tensile strengths of the samples w...

The paper focuses on the gaps in green building rating systems such as LEED with respect to smart building aspects. Most Green building rating system do not recognize the integration of various smart building technologies which are available and alreadyin-use today.
The paper was written with the aim to develop an evaluation system or a rating system specifically for smart buildings in the future.

  This paper explains the benefits of Urban Data Science Education in improving data driving policy-making and highlights the impact of vital use of available open data using a practical demonstration from the Summer-Winter School (SWS) at CEPT University Ahmedabad India.  Good Urban data policies can be an important driver for smart city research and the implementation of good data management practices. Many authors are also becoming interested in the data revolution that is enhancing the way we study and understand cities. It now becomes appropriate to respond to this need in an evidence-informed manner by working with stakeholders to encourage a more resilient approach via education for the younger enthusiast, leading to more transparent, improved, sustainable and safer urban cities. However, the major challenge we foresee is the inability to utilize the large amount of urban data generated daily. With the drive to mobilize more education towards urban data science and analytics,...

Digital elevation models (DEM) are important inputs for topography in modelling floods for remote and inaccessible regions. DEM often lack in accuracy near water bodies and rivers. The objective of this research is to present a DEM correction technique to improve the accuracy of flood simulation and inundation mapping.

Any shelter or structure is basically a product of a design process which depends on many factors. The design process is a collaboration of various professions. Each professional should contribute his part to the design process where the main characteristics of a structure are formed and its qualities and faults are determined. The structural engineer is a part of design team where his valuable input largely influences the quality of the final product. The main professional he will be dealing in the design process will be Architect. It is important to collaborate with the Architect fruitfully for a better design product. The study basically concentrates on identifying the important factors which helps for the creative collaboration between structural engineer and architect and identifying the qualities to be developed by an engineer to play a major role in the design process. The first part of the thesis is aimed at understanding the basic design process, design team, role of structural engineer in the design team, structural design culture and the relationship between engineer and architect. It also consists of identifying the issues in Architect-Engineer collaboration by survey among the practicing engineers and architects. Second part aims at identifying the creative process by studying the works of innovative engineers by the framework developed form the first part and identifying the factors, their personality traits and approach to the conceptual design which made them innovative.

There are two key concerns in developing the proposals. The first is to generate workable solutions that are compatible with the existing physical constraints of the area and the operational constraints of buses and taxis. The second is to make the bus station more accessible to wheelchair users. The study emphasises that the process of bus station design could be enhanced by use of simple analytical tools and hence need not be purely driven by architectural and urban design considerations.

This paper analyses trends in evolution of the urban spatial structure (or urban form) of the city of Ahmedabad, with two key objectives in mind: to generate a quantitative understanding of the evolution of the spatial structure and use such a quantitative understanding to inform the formulation of alternative planning policies for the future. Time-series population data from the Census of India over three decades have been used, which are usually available in most developing countries. In the case of Ahmedabad, the city exhibits a gradual tendency of dispersal, although compared with some other mid-sized metropolitan areas of the world, it is relatively compact. A discussion on the application of the spatial structure analysis to the formulation of alternative planning policies is included. Such analyses for similar cities in India and the developing world in general could be carried out to produce a useful catalogue of cities. However, this is not the objective of the paper, but in due course such literature could be built up.